Reamer with a rolling cutter for enlarging and straightening bore holes



2 Sheets-Sheet 1 INvENTOR V54 4 .Ill

E. B. WILLIAMS, JR BEAMER WITH A ROLLING CUTTER FOR ENLARGING AND STRAIGHTENING BORE HOLES Jan. 25, 1966 Filed Dec. 4, 1965 ATTORNEY.

Jan. 25, 1966 E. B. WILLIAMS, .1R 3,231,033

HEAMER WITH A ROLLING CUTTER FOB. ENLARGING AND STRAIGHTENING BORE HOLES Filed Dec. 4., 1965 2. Sheets-Sheet 2 INVENTOR. .fa/Ward B, W/Y//bms J ATTRNEY United States Patent O 3,231,033 REAMER WITH A RLLING CUTTER FOR EN- LARGING AND STRAIGHTENING BGRE HOLES Edward B. Williams, Jr., Greenville, Tex., assigner of onethird each to Edward B. Williams III, .loseph W. Williams, and David B. Williams, respectively, Greenville,

Tex.

Filed Dec. 4, 1963, Ser. No. 328,013 4 Claims. (Ci. 175-334) This invention relates to a reamer for use in a string of drill pipe employed in the rotary drilling of bore holes into earth formations.

For example, it often becomes necessary to enlarge the diameter of a bore hole being drilled, in order to run a casing which has an inner diameter at least conforming to the diameter of the bore hole being drilled. Also, in drilling bore holes through earth formations, it is diicult to maintain a straight hole, consequently, it is desirable to' ream out and straighten portions of a bore hole at different depths while the drilling continues, to prevent binding and excessive wear of the drill pipe caused by rubbing thereof on the wall of the bore hole.

It is obvious that for economy and speed of drilling, the Vreamer must be capable of passage through diameters corresponding to the diameter of the hole being drilled, and at the same time be capable of rearning to larger diameters at places where rearning is required.

It is, therefore, an object of the present invention to provide a reamer having rotatable cutting means that may be connected into the drilling string anywhere along the length thereof, and which may be run with the drill pipe to depths in the bore hole where the reaming operation is to start, and which is capable of being withdrawn through the diameters of the bore hole corresponding with the diameter of the drill bit being used.

In accomplishing this object, a reamer is provided ha* ing a rota-table cutter or cutters projecting from one side only of the drill pipe, so that the largest transverse width thereof is such that it may pass through circumferences corresponding with the diameter of the bore hole produced by the drill bit that is attached to the lower end of the drilling string. v

Further objects of the invention are to provide a reamer having a rotatable cutter large enough and mounted in a manner to withstand thrusts of the drill pipe thereon; to provide an adequate uid supply for cooling the cutter and removing the cuttings therefrom; and to provide a reamer which permits the drill pipe to yield for relieving lateral thrusts in case the resistance to rotation becomes so excessive as to be destructive to the drilling string.

In accomplishing these and other objects of the invention, I have provided improved structure, the preferred forms of which are illustrated in the accompanying drawings, wherein:

FIG. 1 is a vertical section through a bore hole, and showing a drilling string therein having a drill bit on the lower end thereof and provided along its length with one or more reamers constructed in accordance with the present invention.

FIG. 2 is an enlarged longitudinal section through a reamer and the portions of the drilling string that connect therewith.

FIG. 3 is a perspective view of one of the reamers, particularly illustrating the rolling cutter thereof.

FIG. 4 is a partial cross section on the line 4-4 of FIG. 2, since the rolling cutter is illustrated in plan, and showing the fluid channels in dotted lines, and through which is discharged drilling iiuid to keep the path of the rolling cutter free of cuttings.

3,231,033 Patented Jan. 25, 1966 FIG. 5 is a similar section, taken on the line 5 5 of FIG. 2, showing the channels which discharge the drilling iiuid in full lines, and viewing the rolling cutter from below.

FIG. 6 is a cross section through the bore hole produced by the bit, and showing the reamer passing there` through to a reaming position.

FIG. 7 is a cross section through a reamer having a plurality of cutters and showing passage thereof through a bore hole to be reamed.

Referring more in detail to the drawings:

1 designates a bore hole being drilled through earth formations by a drill bit 2 attached to the end of a string of drill pipe 3. The string of drill pipe is made up of stands of pipe sections 4 that are connected together by tool joints 5. The tool joints S include an internally threaded box 6 (FIG. 2) on one section that usually connects with an externally threaded pin 7 on the next lower section of drill pipe.

In drilling the bore hole 1, it may be necessary to case olf certain of the formations. This is accomplished by running a team-er into the bore hole to enlarge the diameter thereof to accommodate a casing (not shown) having an inner diameter near that of the bore hole. In many instances it is desirable to follow the reamer with the casing, in which case the reamer must be capable of being withdrawn through the casing.

Also, in drilling bore holes it is ditiicult to drill a straight hole, because the drill bit, due to the character of the formations, tends to lead off in various directions (FIG. l), consequently, the drill pipe 3 rotates in a crooked hole and is subject to wear where the tool joints rub on the walls of the bore hole in attempting to follow` the curvature of the crooked hole. For example, the bore hole shown in FIG. l curves toward the right, so thatthe drill pipe rubs with greater pressure on that side of the hole. This places the drill pipe under greater stress and results in failures of the drill pipe, caving of the wall, and wedging of the drill pipe in the bore hole. Therefore, it is desirable to ream the bore hole at such places, to straighten the hole and ease bending conditions of the drill pipe.

To accomplish a reaming operation for running in a casing, the drill pipe is provided with a reamer constructed in accordance with the present invention, to ream out and straighten the inner side of the longitudinal curvature of the bore hole substantially independently of the original axis and permit a larger casing to follow the reamer into the bore hole. In straightening a bore hole, one or more of the reamers 8 may be connected into the drilling string and lowered through the bore hole to the place that the reaming operation is to be started.

The reamer S includes a generally cylindrical body 9, having a diameter substantially conforming to the outer diameter of the drill pipe sections 4 in which it is to be connected. The upper end of the cylindrical body 9 has an externally threaded pin 10, conforming to the pins 7 of the drill pipe sections, to couple the reamer into the box 6 of an upper stand of drill pipe. The lower end of the body has an internally threaded box 11, conforming to the boxes 6 of the stands of drill pipe sections, to connect with the pin 7 of a lower drill pipe section, as shown in FIG. 2. The cylindrical body 9 has an axial bore 12 extending therethrough and through the pin l0 to the box 11, to provide a continuation for iiow of drilling liuid through the string of drill pipe.

Extending from only one side of the cylindrical body is a lateral projection 13, carrying a rolling cutter 14. The projection 13 has an outer arcuate face 15 and radial side faces 16 and 17. The upper face 18 of the projection 13 slopes inwardly and upwardly toward the cylindrical body to join therewith.

In orderthat theV reamer may be passed through the bore hole 1 that is made by the drill bit 2, the overall distance between the outer face of the projection 13 and the opposite side of the cylindrical body is slightly less than the diameter of the bore holel 1" (FIG. 7).

The lower end 19 of theprojection is preferably semicircular. Extendingupwardly and4 inwardly from' the lower end 19 of the projection 13 is a recess or slotZd that continues into the body 9 in-a slight enlargement 2l. The slot Ztlextendsfcoinpletely throughthe projection in the rotary direction to accommodate the rolling cutter therein. The rolling 'cutter' 14 has a disk portion Zifhaving'a conical periphery in the form of teeth-23 provided with chisel shaped edges 24. The teeth Zhave a width along the edges 24corresponding to the amountr that the bore hole 1'isl to be reamed.

The rolling cutter 14 is carriedon a shaft Sthaving its ends carried in a'recess 26in the body member 9 and an openingy 27'in the lateral projection 13; The'rolling cutter 14 is preferablyV journaled on antifriction bearings 2S.

In assembling the parts, the rolling cutter Mis moved into the slot 2li with the antifriction bearings 23 therein and the axial center of the bearings is registered with the recess 26 andthe opening 27. The inner end of the shaft is then inserted'in the opening 27, slid through the bearings and seated in therecess 225, after which the outer end of the shaft is welded to the projection 13, as indicated at 29FIG. 2. It is thus obvious that the lower end 19 of thelug'overlaps the outer'face of the cutter to take the radial thrusts of the drill pipeagainstthe wall of the bore hole so that the cutter rolls freely upon the shaft 2S.

In order to supply drilling Vfluid to the teeth of therolling cutter for cooling the edges 24 and for discharging the cuttings therefrom, the body member 9 of the reamer has a channel Sti-extending from the axial bore 12 to connect with a smaller channel 31 extending upwardly and discharging through a port 32 in the periphery. of the tubular body at an angle (FIG. 3) in front of the rolling cutter; The channel acts as a choke to restrict' the drilling iiuid in the amount desired, and to Vmaintain ,presi surewithin the drill pipe so as to supply the drilling iuid to similar reamers located at lower` positions in the string of drill' pipe and to the drill bit 2.

The modified form of the invention shown in'FlG. 7 conforms to the structure just described, with the exception that there are two lateral projections 33 vandl, each mounting a rolling cutter 35 and .35, respectively. The outer faces 37 ofthe projections are formed on the radii of the bore hole made by the drill bit 2,' so thatthe `reamer can be lowered therethrough to the place where the reaming operationis to start. The axes of the cutters 35and 36 andthe cutters themselves are also set at an angle, so that the cutters will not interfere with loweringof the re'amer into thebore holeV 1, as shown in FIG. 7.

In using the reamer constructed as described for' en-A larginga bore hole to accommodate a casing (not shown) having an` inside diameter conforming toy the original diameter of the borehole, a reamer 8 is connected above the drill bit 2 between any two adjoining stands 4 ofthe drill pipe, and started into the bore hole 1'. The drill pipe is rotated in the usual manner, while drillingfluid is circulateddownwardly through the drill'pipefor discharge through the drill'bit to wash cuttings made by the bit to the top ofthe bore hole by way of the upilow passageway 38. Rotation of the drill pipe gyrates the rollingcutter 14 in a circular path; about the axis of rotation. The cutting action is started by the chisel edges' 24 ofthe'teeth to chip, away the formation and forman annular shoulder 39 that deepens as the reaming progresses.

A portion of the drilling fluid is discharged through the channel Sil and choke channel 31 and port 32 to discharge ina jet againstthe rolling cutter.v

InV using theV reamers for straightening-a crooked'hole, as shown in FIG. l, one or more of the reamers maytbe inserted in the drill pipe at places where the drill pipe tends to rub on the wall of the bore hole, as, for example, on the inside line of curvature, as indicated at 4t) (FIG. 1). The drill pipe, with one or more reamers thereon, is readily lowered through the bore hole of the diameter made by the'drill blt2, since the total diametrical width of the reamer from the lower portion of the rollingA cutters to the opposite side of the cylindrical body 9^is such that it may be lowered through thet borehole, as shown in FIG. 7, to the place where the teaming is to-be started. Since the drill pipe tends to depend in a straightv line; it will crowd the side of the bore hole torbe straightened, and the tensiony in the drillpipe causesrthe rolling cutters to start the reaming action when the drill pipe is rotated. The reamers may be inserted in the drill pipev so that they act in. successiveorderin removing theV side ofi'tlie bore hole sufficiently to straighten the bore llo-leY andl relieve bending'ot the'drill pipe, as shown in FIG. l'.

It is obvious that withthe rnountingfofr the rolling cutter as above described, the: cutteris splayed outwardlyl and downwardly, so that the teeth'whicharefeiiectiverin rearn ing, cut a path of substantially greater diameterV thanl the diameter of the bore hole producedfby the drill bit'l What I claim and'desire to=secure"byLettersi'Patentfis:

l. In combination with a stringf ofi'rotaryv drill pipe having a drill-bit axially connected' ontheflowerend-for drilling a bore hole upon. rotation of? the string ofldll pme,

a reamer for stralghteningthebore holefhavingv a-cylii1- drical body substantially theL same= diameter` as ythe diameter of the drill pipe,

connections on` respective ends off thecylindrical body for connecting said body. of the ream'eh coaxially into the string of drill pipe at azpointspacedabove the` drill bit,

a rolling cutter having a disk portion provided? with peripheral teeth having inwardly extending cutting edges, and

`means for journaling the cutter onl one side of'sald body for rotation onanaxis substantially transversely ofy the axis of the drill pipe yto'cause-'the cutting edges of the reamer to roll along apath' circumferentially of the axis ofthe bore hole made by the drill bit but on acenter independently' of said" axis.

2. In combination with a stringvof rotary1d'rill-pi'pe having adrill'b-it axially connected on th'elowerf end" for drilling Va bore hole upon rotation of the .stringofdrill rule,

a reamer for straightening theboreh'olehaving acylin drical body substantially. the: sarnediameter as the diameter of the drill pipe,

connections on respectiveends ofthe cylindrical'body for connectingsaidrbody ofthereamer coaxiall'y into the. stringof drill pipe at a-.point spaced? above the dri-ll bit,

said. cylindrical bodyI` having aprojection extending from only one side thereofandf'havingl an arcuate outer face concentric withthe. rotationalaxiseoffthe drill pipe for contact with t-he wall of the-bore hole drilled. by the bit and said3cylind`rical bodyh-aving a width between said arcuate face Vandthev opposite side of said bodysubstantiallyfequal` to the, diameter of the drill bit,: whereby' the drillv pipe withY the reamer connected therein can be loweredintoA the Kbore holefprev-iouslymade by. the, bit,

saidprojectionv having a slot extending upwardly. and

inwardly from the under face thereof,.

a rolling cuttery having a disk portion rotatable in. the slot and having peripheral' teethV with outer faces located in the plane of the arcuate face of theprojection and having inwardly extending cuttingedges, and

means for journaling the cutter-ln said slotrforlrotation on an axis substantiallyl transversely'of the-axis of the drill pipe to causev cutting-edges `ofthe teeth of the reamer to roll along a circular path circumferentially of the axis of the bore hole made by the dr-ill bit but on a center independently of said axis of the bore hole made by the drill bit.

said cylindrical body having a projection extending from one side only thereof and provided with an arcuate outer face concentric with the rotational axis of the d'ril-l pipe for contact with the wall of the bore -a shaft journaling the cutter thereon and having ends carried in aligning openings in the projection and in said body at the respective s-ides of the disk portion and on which the cutter turns with the cutting edges 3. In combination with a string of rotary drill pipe 5 of the teeth rolling along a circular path having a having a drill bit axially connected on the lower end for center substantially independent of the axis of the drilling a bore hole in an earth formation upon rotation of bore hole made by the drill bit while the thrust the string of drill pipe, of the drill pipe against the wall of the bore hole is a reainer for straightening the bore hole having a cylintaken by said arcuate face, leaving the cutter free drical body substantially the sarne diameter as the 10 to rotate on said shaft and cut away the formation on diameter of the drill pipe, the inner side of the longitudinal curvature of the connections on respective ends of the cylindrical body `bore hole.

for connecting said body `of the reamer axially into 4. A combination as described in claim 3,

the string of drill pipe at a point spaced above the in which the cylindrical body of the reamer has an axial drill bit, bore forming a continuation of flow passageways for drilling fluid in the drill pipe sections and a channel connected therewith and discharging below the rolling cutter to wash cuttings made by the teeth thereof.

hole drilled by the bit and said cylindrical body having a Widt-h between said arcuate face of the projection and the opposite side of said body substantially equal to the diameter of the drill bit, whereby the References Cited by the Examiner UNITED STATES PATENTS drill pipe with the reamer connected therein can 1399863 12/1921 Hughes 175-344 |be lowered into the bore hole previously made by 1637594 8/1927 Stewart 175n-349 X 'the bit 1,653,928 12/1927 Reed l75-349 X said projection having a slot extending upwardly and 1906056 4/1933 Gohsh 175-335 X 2,030,722 2/1936 Scott 175--335 X mwa-rdly from the under face thereof, a rollin critter havin a disk ortion rotatable in the 2249732 7/1941 Green 175-345 X g g p 3,094,177 6/ 1963 Williams 175-334 slot and having peripheral teeth With outer faces located in the plane of the arcuate face of the projection and having inward-ly extending cutting edges, and

CHARLES E. OCONNELL, Primary Examiner.

D. H. BROWN, Assistant lExaminer. 

1. IN COMBINATION WITH A STRING OF ROTARY DRILL PIPE HAVING A DRILL BIT AXIALLY CONNECTED ON THE LOWER END FOR DRILLING A BORE HOLE UPON ROTATION OF THE STRING OF DRILL PIPE, A REAMER FOR STRAIGHTENING THE BORE HOLE HAVING A CYLINDRICAL BODY SUBSTANTIALLY THE SAME DIAMETER AS THE DIAMETER OF THE DRILL PIPE, CONNECTIONS ON RESPECTIVE ENDS OF THE CYLINDRICAL BODY FOR CONNECTING SAID BODY OF THE REAMER COAXIALLY INTO THE STRING OF DRILL PIPE AT A POINT SPACED ABOVE THE DRILL BIT, A ROLLING CUTTER HAVING A DISK PORTION PROVIDED WITH PERIPHERAL TEETH HAVING INWARDLY EXTENDING CUTTING EDGES, AND MEANS FOR JOURNALING THE CUTTER ON ONE SIDE OF SAID BODY FOR ROTATION ON AN AXIS SUBSTANTIALLY TRANSVERSELY OF THE AXIS OF THE DRILL PIPE TO CAUSE THE CUTTING EDGES OF THE REAMER TO ROLL ALONG A PATH CIRCUMFERENTIALLY OF THE AXIS OF THE BORE HOLE MADE BY THE DRILL BIT BUT ON A CENTER INDEPENDENTLY OF SAID AXIS. 